1. Field of the Invention
The present invention relates to an optical recording apparatus, and more particularly to an optical recording apparatus for recording data by irradiating an optical recording medium with a light beam.
2. Description of the Related Art
A disc-shaped recording medium, such as an optical disc or a magneto-optical disc, utilizing the method of optical or magneto-optical signal recording/reproducing, has been well known in the art. As such disc-shaped recording medium, there are known a recording medium of the read-only-memory type (ROM) such as a so-called compact disc (CD), a so-called write once type recording medium on which data can be written only once by the user, and a so-called overwrite type disc, such a magneto-optical disc, on which data re-recording is possible.
In optical discs such as those of the compact disc family (e.g., Audio CD, CD ROM, Video CD, CD-I, Magneto-optic CD (CD-MO), Mini discs (MD), etc.), grooves are formed on both sides of its recording track and convex and concave shallow depressions or pits are formed as information recorded thereon.
In fabricating such optical discs, a photoresist, for example, is applied to the surface of a glass substrate, the photoresist is exposed to pattern irradiation, and then developed, whereby, convex and concave photoresist patterns corresponding to the grooves or pits are formed. Then, after the etching of the surface of the substrate with the photoresist used as a mask, a plating process is performed on such convex or concave surface, and, thus, a CD-disc master is fabricated for making a stamper for forming optical discs.
As shown in FIG. 1, where a schematic structural diagram of a conventional optical recording apparatus 10 is depicted, a laser beam 12 for recording is emitted from a laser beam source 14 such as an argon-ion laser. The laser 14 is fed from a laser supply 16. The beam 12 passes through an optical system 18 that comprises means 20 for controlling beam intensity and deflection, modulating means 22, and an optical means 24 that lets the laser beam through to a recording chamber 26, as well as to an E-O-E board 28, and to a TV camera 30 connected to a TV monitor (not shown). The modulating means 22 is responsive to an electric signal representing the information to be recorded on a CD.
Conventional optical recording apparatus are expensive. Additionally, a work with laser light, which can be viewed end on or by reflection, may be harmful to viewers' vision, if performed permanently during long periods of time, and inflict damage on their eyes. Also, service life of laser installations is not believed to be long enough, especially where their high cost is taken into account.